Speed-changing and reversing gear.



.spective pins.

NITED STATES HARVEY EZRA BROWN,

or sLoUerI, ENGLAND.

SPEED-CHANGING AND REVERSING GEAR.

SPECIFICATION forming part of Letters Patent No. 686,256, dated November12, 1901. Application filed March 22, 1901. Serial No. 52,424. (Nomodel.)

To on whom it may concern.-

Be it known that I, HARVEY EZRA BBOVVN, manager, a citizen of the UnitedStatesof North America, residing at Gotha \Vorks, Slough,.England, haveinvented certain new and useful Improvements in Speed-Changing andReversing Gears, (for which I have made application for patent in GreatBritain, No. 15,036, dated August 22, 1900,) of which the following is aspecification.

This invention relates to change-speed and reversing gears, the objectbeing to provide an apparatus which will admit of an infinite gradationof speed between any desired limits in either direction and which shallbe compact and readily controlled by the manipulation of a single handwheel or lever.

The invention is illustrated in the accompanying drawings, in which-Figures 1 and 2 are respectively longitudinal and transverse sectionalelevations, the planes of section being indicated by the lines A B O D.

In carrying my invention into efiect a worm or pinion a is fixed to therotating shaft 1), whence the power from the prime mover is derived andwhich is hereinafter called the driving-shaft. The'said worm or pinionengages with a worm-wheel or spur-wheel c, which is preferably mountedaxially upon the shaft h, to which it is desired to impart a Va riablespeed and which is hereinafter called the driven shaft, the saidworm-wheel being free to rotate independentlyupon the said shaft. Fixedto the said worm-wheel c or forming an integral part of same is provideda disk or plate d, in the face of which pins 6 are provided to carry oneor more planetwheels f, which revolve freely upon their re- The planetwheel or wheels engage simultaneously, in the first place, with acentralsnn-wheel g, which is keyed or otherwise fixed to the drivenshaft h, and, in the second place, with an annular wheel k, which ispreferably mounted upon the driven shaft, but free to revolveindependently thereon, as in the case of the worm-wheel o. Fixed to theannular wheel 7a or forming an integral part of same is provided aworm-wheel Z, engaging with a worm m, the said worm and wheel beingpreferably made with such a pitch that the worm-wheel on being given atendency to revolve would be very nearly or quite capable of driving theworm as desired.

Now it is evident that if the motion of the driving-shaft b be impartedthrough the gearing described to the disk (1, carrying the planet wheelor wheels f, the result will be to rotate the sun-wheel g, provided thatthe annular wheel k is stationary, it being wellun derstood that in thisform of sun-and-planct gear the annular wheel forms the fulcrum or pointof purchase whence the motion of the planet-wheel reacts upon thesun-wheel. The annular wheel 7t is held stationary so long as theworm-gear Z m, fixed thereto, is not permitted to rotate. If nowsuitable means are provided to rotate the wormgear Z m, therebyreleasing the annular wheel 7:; at any desired gradation of speed in thesame direction as that in which the planet-wheel frevolves, it will bereadily seen that complete control is obtained for the resultant speedof the sun-wheel g, and thereby that of the driven shaft h.

For controlling the speed of the annular wheel 70 the driving-shaft b isconnected by bevel-gears 0 p to a shaft g, at one end of which ismounted a friction-disk 1'. Upon one end of the worm-shaft 3, upon whichthe controlling-worm m is mounted, is provided a friction-wheel i whoseperiphery is in frictional contact with the friction-disk r. Thefriction-wheel is arranged to slide longitudinally along the worm-shaftupon a feather u, and a prolongation '1) forms a sleeve in which agroove to is provided as a means of engagement with a lever or otherdevice for controlling the longitudinal movement of the fric-'tion-wheel, whether the same is rotated or not, as is usual in suchcases. By means of the longitudinal movement described thefriction-wheel t may be caused to travel at will across the face of thefriction-disk r from center to periphery of the same. So long as thefriction-wheel, being in contact with the retating disk, is held at thecenter of the latter there will be no rotation of the worm-shaft s,carrying the controlling-worm m, and consequently the annular wheel 7;remains stationary, resulting in the highest prearranged speed of thesun-wheel g and driven shaft 7L. If then the friction-wheel i betraversed across the friction-disk r outwardly toward its pcriphery, itwill be readily seen that a gradually-increasing motion is imparted tothe annular wheel 7c, producing, in effect, a differentiation in thesun-and-planet gear, with a resulting and corresponding decrease ofspeed in the sun-wheel g and driven shaft h. By suitably arranging theproportions of the friction-gear and the extent of the longitudinaltravel of the friction-wheel a point will be reached in suchlongitudinal travel where the resulting speed of the annular wheel iswill be equal to that of the disk d, carrying the planet-wheels f, whichmay be described as the normal or most favorable speed for running thedriven shaft h. Beyond this point the resulting speed of the annularwheel 70 will be'found to exceed that of the planetwheel disk d, and apoint will be reached where they differentiation in the sun-andplanetgear will cancel the turning moment of the sun-wheel g and result incessation of movement in the driven shaft h. Beyond this again theeffect will be to reverse the original direction of rotation of thedriven shaft.

Up to the point where the cessation of rotation of the driven shaft isattained very little, if any, power is required to rotate the annularwheel 70, the motion being, in fact, more of the nature of a releaserather than a drive, and the friction-gear is relied on. Beyond thatpoint when actual driving of the annular wheel is required a toothedgear a: is provided, which is preferably putinto operation by means of aclutch y, so arranged as to come automatically into gear when thefriction-wheel t has reached the limit of its a carrier for theplanet-wheel, a toothed wheel meshing with the planet-wheel and meansfor driving the toothed wheel comprising friction driving means andpositive driving means and means of adjustment whereby either thepositive orthe friction driving means may be made to act, substantiallyas described.

2. In combination, the main shaft h, a sunwheel fixed thereon, aplanet-wheel meshing with the sun-wheel, a disk arranged at one side ofsaid sun and planet wheels on the shaft, and carrying the planet-wheel,a toothwheel surrounding the sun and planet wheels and meshing with thelatter, a disk on the opposite side of the sun and planet wheels fromthe disk first mentioned and carrying the toothed wheel, worm-gearingfor each of said disks, the shafts b and sconnected with the saidworm-gearing, and the adjustable friction driving means between the twoshafts b and s, substantially as described.

3. In combination, the main shaft, a sunwheel thereon, a planet-wheel, aloose disk on the shaft carrying said planet-wheel, a toothed wheel 70meshing with the planetwheel, gearingfor driving said toothed wheel 70,including friction-disks, one of which is splined on its shaft to beadjusted across the face of the other friction-disk, apositivelyoperated gear-wheel loosely running on the shaft of theadjustable friction-disk and the clutch parts between said adjustablefrictiondisk and the positively-operated gear, substantially asdescribed.

4. In combination, the shaft, a sun-wheel fixed thereon, a planet-wheel,means for carrying and moving said planet-wheel, a toothed wheel isengaging said planet-wheel and means for driving said toothed wheelcomprising a shaft, a bevel-gear thereon, a friction-disk adj ustablyheld on the said shaft, clutching parts between the friction-disk andthe bevelgear, and a second bevel-gear for driving said loosebevel-gear, said second bevel-gear carrying a friction-surface for thefriction-disk,

substantially as described.

5. In combination, a main shaft, a toothed wheel fixed thereto, aplanet-wheel in mesh with the same, a disk carrying the latter, meansfor driving the disk includingacounter-shaft b, a toothed wheel in meshwith the planet-wheel, means-for controlling the rotation thereofincluding a worm-shaft, a friction-wheel on the worm-shaft, a frictionconnection between friction-wheel and the counter-shaftb and positivedrive mechanism interposed between said counter-shaft b and thefriction-wheel, substantially as described.

In testimony whereof I have hereunto set my hand in presence of twowitnesses.

HARVEY EZRA BROWN.

Witnesses:

A. W. MATHYS, WALTER J. SKERTEN.

